John Calvin's Commentary on the Bible - Psalms 18:6
Verse 6 6.In my distress, etc. It was a very evident proof of uncommon faith in David, when, being almost plunged into the gulf of death, he lifted up his heart to heaven by prayer. Let us therefore learn, that such an example is set before our eyes, that no calamities, however great and oppressive, may hinder us from praying, or create an aversion to it. It was prayer which brought to David the fruits or wonderful effects of which he speaks a little after, and from this it appears still more... read more
Adam Clarke's Commentary on the Bible - Psalms 18:15
The channels of water were seen - This must refer to an earthquake; for in such cases, the ground being rent, water frequently gushes out at the fissures, and often rises to a tremendous height. Whole rivers were poured out of the chasms made by the earthquake in Jamaica, A. D. 1694; and new lakes of water were formed, covering a thousand acres of land! read more